improve transaction deserialization strictness (#1457)
improve transaction deserialization strictness (#1457)

* improve deserialization strictness

- all bitcoin txes must have at least 1 output; this is a consensus rule.
- don't ignore garbage after transaction ends.

`can_read_more` function borrowed from https://github.com/spesmilo/electrum/commit/71ce7cce6d

* Added catch of serializationerror to tx input fetcher

fyookball/electrum,fyookball/electrum,fyookball/electrum